Merlin imagined many ways that Arthur could react to finding out about his magic. He imagined anger, fear, feelings of hurt and betrayal. On more optimistic days he imagined acceptance and understanding. Never had he imagined that it would send Arthur into an irrational fit of hysterics.
"Well of course you're a sorcerer! It turns out Morgana was actually my sister, my uncle was working with her the whole time, my father's wife was a troll, the man who killed my father actually tried to save him and my wife cheated on me with my most respectable knight. So why shouldn't my best friend turn out to be a sorcerer?!" Arthur gasped for breath in the midst of his rant, "What next? Gwaine is really a noble, Leon is secretly a woman and Percival is actually two people with one standing on the other's shoulders?"
"Umm, well, I don't know about Leon and Percival but Gwaine really is a noble," Merlin timidly supplied.
Arthur just stared at him.
"GWAINE!"
A short time later...
"Why didn't you tell me you were a noble?!"
"What? How did you find out?"
"A sorcerer told me!" Arthur shouted, pacing irately about Gwaine's chambers.
"A sorcerer?"
"My life is complicated!"
"Right then," said Gwaine, not knowing what to say.
"This is all your fault!"
"What is?" Gwaine asked bewildered.
"Tell me honestly," Arthur started, "is Leon a woman?"
That was about the last thing he expected to come out of Arthur's mouth.
"What?!"
"Is there no one I can actually trust?"
"Look Arthur, I didn't tell you I was a noble because I didn't want any special treatment, it doesn't mean you can't trust me."
"And what about the others?"
"Others?"
"Everyone I've ever known!"
"Everyone has secrets, Arthur."
"I don't," Arthur shouted petulantly.
"You would if Merlin was any good at keeping them for you. I bet YOU would never have told us about the donkey ears or the time you borrowed Morgana's…"
"Merlin is very good at keeping secrets!" He shouted.
"Oh really? So how did you find out I was a noble?"
"That is. Well."
"And did he manage to keep his magic a secret from you?"
"Until today he did."
"Seriously? You didn't know? Maybe it's not that people keep secrets from you; maybe you're just thick."